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  • Artigo IPEN-doc 28103
    Evaluation of the anti-caries effect beyond the critical enamel pH of preventive treatment of fluoride associated with Nd:YAG laser irradiation
    2021 - JUVINO, AMANDA C.; ROMANO, MARIANA; ALVES, NATHALIA Z.; FREITAS, THAIS R.; ZAMATARO, CLAUDIA B.; ZEZELL, DENISE M.
    This study aimed to evaluate the anti-caries effect of fluoride associated with Nd:YAG laser irradiation in the h-eatment of enamel Eight groups (n = S) were analyzed: Negative Control pH 4.5; Negative control pH 4; Fluoride pH 4.5; Fluoride pH 4; Nd-YAG pH 4.5; Nd-YAG pH 4; (Fluoride + Nd-YAG) pH 4.5 and (Fluoride + Nd-YAG) pH 4. All samples were analyzed by Scanning Electron Microscopy (SEM) before and after the cycle. Quantification of phosphorus in the cycling solutions was carried out using the colorimetric method, as an indication of enamel demineralization. The anti-caries effect of the Fluoride + Nd: YAG treatment in addition to the critical pH of the enamel can be observed in the morphological analysis, however in the analysis of the demineralization solutions, the amount of phosphorus showed a difference only in the Fluoiide group compared to the others in the investigative pH.
  • Artigo IPEN-doc 27710
    Morphological, optical, and elemental analysis of dental enamel after debonding laminate veneer with Er,Cr:YSGG laser
    2021 - ZANINI, NATHALIA A.; RABELO, THAIS F.; ZAMATARO, CLAUDIA B.; CARAMEL-JUVINO, AMANDA; ANA, PATRICIA A.; ZEZELL, DENISE M.
    Laminate veneer removal is becoming a routine procedure at the dental clinic and the use of laser can facilitate its removal. This work aimed to evaluate the morphological, elemental, and optical changes in the remaining enamel after veneer removal using Er,Cr:YSGG laser. Forty‐four enamel slabs were prepared and randomly distributed into nine experimental groups, for bonding using lithium disilicate laminates with three different luting agents (Variolink Veneer, RelyX U200, and RelyX Veneer). Then each agent was debonded using Er,Cr:YSGG laser (2.78 μm) using two different protocols:3.5 W, 48.14 J/cm2, 20 Hz non‐contact and 3.0 W, 48.14 J/cm2, 20 Hz non‐contact. The morphological, optical, and elemental analysis of enamel was performed before cementation and after laser debonding, using scanning electron microscopy (SEM), optical coherence tomography (OCT), and energy‐dispersive X‐ray spectroscopy (EDS). The level of statistical significance adopted was 5%. The EDS analysis of enamel after debonding revealed a significant increase in silane and carbon, as well as a decrease in calcium and phosphate contents. Analysis showed the presence of residual cement in most experimental groups but the morphological analysis showed alteration of the enamel's prisms only in the groups that used RelyX Veneer and Variolink Veneer cements. There was no evidence of deleterious morphological changes resulting from irradiation. However, an increase in the optical attenuation coefficient by the OCT was observed due to the presence of the remaining cement. It can be concluded that the Er,Cr:YSGG laser, in the mean powers used, is efficient for veneer removal without causing deleterious effects for the enamel.